/*
 * Copyright (C) 2005 - 2013 MaNGOS <http://www.getmangos.com/>
 *
 * Copyright (C) 2008 - 2013 Trinity <http://www.trinitycore.org/>
 *
 * Copyright (C) 2010 - 2013 ProjectSkyfire <http://www.projectskyfire.org/>
 *
 * Copyright (C) 2011 - 2013 ArkCORE <http://www.arkania.net/>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "Common.h"

#ifdef _WIN32
#include <winsock2.h>
#endif
#include <mysql.h>

#include "MySQLConnection.h"
#include "MySQLThreading.h"
#include "QueryResult.h"
#include "SQLOperation.h"
#include "PreparedStatement.h"
#include "DatabaseWorker.h"
#include "Timer.h"
#include "Log.h"

MySQLConnection::MySQLConnection(MySQLConnectionInfo& connInfo) :
        m_reconnecting(false), m_prepareError(false), m_queue(NULL), m_worker(
                NULL), m_Mysql(NULL), m_connectionInfo(connInfo), m_connectionFlags(
                CONNECTION_SYNCH) {
}

MySQLConnection::MySQLConnection(ACE_Activation_Queue* queue,
        MySQLConnectionInfo& connInfo) :
        m_reconnecting(false), m_prepareError(false), m_queue(queue), m_Mysql(
                NULL), m_connectionInfo(connInfo), m_connectionFlags(
                CONNECTION_ASYNC) {
    m_worker = new DatabaseWorker(m_queue, this);
}

MySQLConnection::~MySQLConnection() {
    ASSERT (m_Mysql); /// MySQL context must be present at this point

    sLog->outSQLDriver("MySQLConnection::~MySQLConnection()");
    for (size_t i = 0; i < m_stmts.size(); ++i)
        delete m_stmts[i];

    for (PreparedStatementMap::const_iterator itr = m_queries.begin();
            itr != m_queries.end(); ++itr) {
        free((void *) m_queries[itr->first].first);
    }

    mysql_close(m_Mysql);
    Unlock(); /// Unlock while we die, how ironic
}

void MySQLConnection::Close() {
    /// Only close us if we're not operating
    delete this;
}

bool MySQLConnection::Open() {
    MYSQL *mysqlInit;
    mysqlInit = mysql_init(NULL);
    if (!mysqlInit) {
        sLog->outError("Could not initialize Mysql connection to database `%s`",
                m_connectionInfo.database.c_str());
        return false;
    }

    int port;
    char const* unix_socket;

    mysql_options(mysqlInit, MYSQL_SET_CHARSET_NAME, "utf8");
#ifdef _WIN32
    if (m_connectionInfo.host == ".") // named pipe use option (Windows)
    {
        unsigned int opt = MYSQL_PROTOCOL_PIPE;
        mysql_options(mysqlInit, MYSQL_OPT_PROTOCOL, (char const*)&opt);
        port = 0;
        unix_socket = 0;
    }
    else // generic case
    {
        port = atoi(m_connectionInfo.port_or_socket.c_str());
        unix_socket = 0;
    }
#else
    if (m_connectionInfo.host == ".") // socket use option (Unix/Linux)
            {
        unsigned int opt = MYSQL_PROTOCOL_SOCKET;
        mysql_options(mysqlInit, MYSQL_OPT_PROTOCOL, (char const*) &opt);
        m_connectionInfo.host = "localhost";
        port = 0;
        unix_socket = m_connectionInfo.port_or_socket.c_str();
    } else // generic case
    {
        port = atoi(m_connectionInfo.port_or_socket.c_str());
        unix_socket = 0;
    }
#endif

    m_Mysql = mysql_real_connect(mysqlInit, m_connectionInfo.host.c_str(),
            m_connectionInfo.user.c_str(), m_connectionInfo.password.c_str(),
            m_connectionInfo.database.c_str(), port, unix_socket, 0);

    if (m_Mysql) {
        if (!m_reconnecting) {
            sLog->outSQLDriver("MySQL client library: %s",
                    mysql_get_client_info());
            sLog->outSQLDriver("MySQL server ver: %s ",
                    mysql_get_server_info(m_Mysql));
            if (mysql_get_server_version(m_Mysql) != mysql_get_client_version())
                sLog->outSQLDriver(
                        "[WARNING] MySQL client/server version mismatch; may conflict with behaviour of prepared statements.");
        }

        sLog->outDetail("Connected to MySQL database at %s",
                m_connectionInfo.host.c_str());
        mysql_autocommit(m_Mysql, 1);

        // set connection properties to UTF8 to properly handle locales for different
        // server configs - core sends data in UTF8, so MySQL must expect UTF8 too
        mysql_set_character_set(m_Mysql, "utf8");
        return PrepareStatements();
    } else {
        sLog->outError("Could not connect to MySQL database at %s: %s\n",
                m_connectionInfo.host.c_str(), mysql_error(mysqlInit));
        mysql_close(mysqlInit);
        return false;
    }
}

bool MySQLConnection::PrepareStatements() {
    DoPrepareStatements();
    for (PreparedStatementMap::const_iterator itr = m_queries.begin();
            itr != m_queries.end(); ++itr)
        PrepareStatement(itr->first, itr->second.first, itr->second.second);
    return !m_prepareError;
}

bool MySQLConnection::Execute(const char* sql) {
    if (!m_Mysql)
        return false;

    {
        uint32 _s = 0;
        if (sLog->GetSQLDriverQueryLogging())
            _s = getMSTime();

        if (mysql_query(m_Mysql, sql)) {
            uint32 lErrno = mysql_errno(m_Mysql);

            sLog->outSQLDriver("SQL: %s", sql);
            sLog->outSQLDriver("ERROR: [%u] %s", lErrno, mysql_error(m_Mysql));

            if (_HandleMySQLErrno(lErrno)) // If it returns true, an error was handled successfully (i.e. reconnection)
                return Execute(sql); // Try again

            return false;
        } else if (sLog->GetSQLDriverQueryLogging()) {
            sLog->outSQLDriver("[%u ms] SQL: %s",
                    getMSTimeDiff(_s, getMSTime()), sql);
        }
    }

    return true;
}

bool MySQLConnection::Execute(PreparedStatement* stmt) {
    if (!m_Mysql)
        return false;

    uint32 index = stmt->m_index;
    {
        MySQLPreparedStatement* m_mStmt = GetPreparedStatement(index);
        ASSERT(m_mStmt); // Can only be null if preparation failed, server side error or bad query
        m_mStmt->m_stmt = stmt; // Cross reference them for debug output
        stmt->m_stmt = m_mStmt; // TODO: Cleaner way

        stmt->BindParameters();

        MYSQL_STMT* msql_STMT = m_mStmt->GetSTMT();
        MYSQL_BIND* msql_BIND = m_mStmt->GetBind();

        uint32 _s = 0;
        if (sLog->GetSQLDriverQueryLogging())
            _s = getMSTime();

        if (mysql_stmt_bind_param(msql_STMT, msql_BIND)) {
            uint32 lErrno = mysql_errno(m_Mysql);
            sLog->outSQLDriver("SQL(p): %s\n [ERROR]: [%u] %s",
                    m_mStmt->getQueryString(m_queries[index].first).c_str(),
                    lErrno, mysql_stmt_error(msql_STMT));

            if (_HandleMySQLErrno(lErrno)) // If it returns true, an error was handled successfully (i.e. reconnection)
                return Execute(stmt); // Try again

            m_mStmt->ClearParameters();
            return false;
        }

        if (mysql_stmt_execute(msql_STMT)) {
            uint32 lErrno = mysql_errno(m_Mysql);
            sLog->outSQLDriver("SQL(p): %s\n [ERROR]: [%u] %s",
                    m_mStmt->getQueryString(m_queries[index].first).c_str(),
                    lErrno, mysql_stmt_error(msql_STMT));

            if (_HandleMySQLErrno(lErrno)) // If it returns true, an error was handled successfully (i.e. reconnection)
                return Execute(stmt); // Try again

            m_mStmt->ClearParameters();
            return false;
        }

        if (sLog->GetSQLDriverQueryLogging())
            sLog->outSQLDriver("[%u ms] SQL(p): %s",
                    getMSTimeDiff(_s, getMSTime()),
                    m_mStmt->getQueryString(m_queries[index].first).c_str());

        m_mStmt->ClearParameters();
        return true;
    }
}

bool MySQLConnection::_Query(PreparedStatement* stmt, MYSQL_RES **pResult,
        uint64* pRowCount, uint32* pFieldCount) {
    if (!m_Mysql)
        return false;

    uint32 index = stmt->m_index;
    {
        MySQLPreparedStatement* m_mStmt = GetPreparedStatement(index);
        ASSERT(m_mStmt); // Can only be null if preparation failed, server side error or bad query
        m_mStmt->m_stmt = stmt; // Cross reference them for debug output
        stmt->m_stmt = m_mStmt; // TODO: Cleaner way

        stmt->BindParameters();

        MYSQL_STMT* msql_STMT = m_mStmt->GetSTMT();
        MYSQL_BIND* msql_BIND = m_mStmt->GetBind();

        uint32 _s = 0;
        if (sLog->GetSQLDriverQueryLogging())
            _s = getMSTime();

        if (mysql_stmt_bind_param(msql_STMT, msql_BIND)) {
            uint32 lErrno = mysql_errno(m_Mysql);
            sLog->outSQLDriver("SQL(p): %s\n [ERROR]: [%u] %s",
                    m_mStmt->getQueryString(m_queries[index].first).c_str(),
                    lErrno, mysql_stmt_error(msql_STMT));

            if (_HandleMySQLErrno(lErrno)) // If it returns true, an error was handled successfully (i.e. reconnection)
                return _Query(stmt, pResult, pRowCount, pFieldCount); // Try again

            m_mStmt->ClearParameters();
            return false;
        }

        if (mysql_stmt_execute(msql_STMT)) {
            uint32 lErrno = mysql_errno(m_Mysql);
            sLog->outSQLDriver("SQL(p): %s\n [ERROR]: [%u] %s",
                    m_mStmt->getQueryString(m_queries[index].first).c_str(),
                    lErrno, mysql_stmt_error(msql_STMT));

            if (_HandleMySQLErrno(lErrno)) // If it returns true, an error was handled successfully (i.e. reconnection)
                return _Query(stmt, pResult, pRowCount, pFieldCount); // Try again

            m_mStmt->ClearParameters();
            return false;
        }

        if (sLog->GetSQLDriverQueryLogging())
            sLog->outSQLDriver("[%u ms] SQL(p): %s",
                    getMSTimeDiff(_s, getMSTime()),
                    m_mStmt->getQueryString(m_queries[index].first).c_str());

        m_mStmt->ClearParameters();

        *pResult = mysql_stmt_result_metadata(msql_STMT);
        *pRowCount = mysql_stmt_num_rows(msql_STMT);
        *pFieldCount = mysql_stmt_field_count(msql_STMT);

        return true;
    }
}

ResultSet* MySQLConnection::Query(const char* sql) {
    if (!sql)
        return NULL;

    MYSQL_RES *result = NULL;
    MYSQL_FIELD *fields = NULL;
    uint64 rowCount = 0;
    uint32 fieldCount = 0;

    if (!_Query(sql, &result, &fields, &rowCount, &fieldCount))
        return NULL;

    return new ResultSet(result, fields, rowCount, fieldCount);
}

bool MySQLConnection::_Query(const char *sql, MYSQL_RES **pResult,
        MYSQL_FIELD **pFields, uint64* pRowCount, uint32* pFieldCount) {
    if (!m_Mysql)
        return false;

    {
        uint32 _s = 0;
        if (sLog->GetSQLDriverQueryLogging())
            _s = getMSTime();

        if (mysql_query(m_Mysql, sql)) {
            uint32 lErrno = mysql_errno(m_Mysql);
            sLog->outSQLDriver("SQL: %s", sql);
            sLog->outSQLDriver("ERROR: [%u] %s", lErrno, mysql_error(m_Mysql));

            if (_HandleMySQLErrno(lErrno)) // If it returns true, an error was handled successfully (i.e. reconnection)
                return _Query(sql, pResult, pFields, pRowCount, pFieldCount); // We try again

            return false;
        } else if (sLog->GetSQLDriverQueryLogging()) {
            sLog->outSQLDriver("[%u ms] SQL: %s",
                    getMSTimeDiff(_s, getMSTime()), sql);
        }

        *pResult = mysql_store_result(m_Mysql);
        *pRowCount = mysql_affected_rows(m_Mysql);
        *pFieldCount = mysql_field_count(m_Mysql);
    }

    if (!*pResult)
        return false;

    if (!*pRowCount) {
        mysql_free_result(*pResult);
        return false;
    }

    *pFields = mysql_fetch_fields(*pResult);

    return true;
}

void MySQLConnection::BeginTransaction() {
    Execute("START TRANSACTION");
}

void MySQLConnection::RollbackTransaction() {
    Execute("ROLLBACK");
}

void MySQLConnection::CommitTransaction() {
    Execute("COMMIT");
}

bool MySQLConnection::ExecuteTransaction(SQLTransaction& transaction) {
    std::list<SQLElementData> const& queries = transaction->m_queries;
    if (queries.empty())
        return false;

    BeginTransaction();

    std::list<SQLElementData>::const_iterator itr;
    for (itr = queries.begin(); itr != queries.end(); ++itr) {
        SQLElementData const& data = *itr;
        switch (itr->type) {
        case SQL_ELEMENT_PREPARED: {
            PreparedStatement* stmt = data.element.stmt;
            ASSERT(stmt);
            if (!Execute(stmt)) {
                sLog->outSQLDriver(
                        "[Warning] Transaction aborted. %u queries not executed.",
                        (uint32) queries.size());
                RollbackTransaction();
                return false;
            }
        }
            break;
        case SQL_ELEMENT_RAW: {
            const char* sql = data.element.query;
            ASSERT(sql);
            if (!Execute(sql)) {
                sLog->outSQLDriver(
                        "[Warning] Transaction aborted. %u queries not executed.",
                        (uint32) queries.size());
                RollbackTransaction();
                return false;
            }
        }
            break;
        }
    }

    CommitTransaction();
    return true;
}

MySQLPreparedStatement* MySQLConnection::GetPreparedStatement(uint32 index) {
    ASSERT(index < m_stmts.size());
    MySQLPreparedStatement* ret = m_stmts[index];
    if (!ret)
        sLog->outSQLDriver(
                "ERROR: Could not fetch prepared statement %u on database `%s`, connection type: %s.",
                index,
                m_connectionInfo.database.c_str(),
                (m_connectionFlags & CONNECTION_ASYNC) ?
                        "asynchronous" : "synchronous");

    return ret;
}

void MySQLConnection::PrepareStatement(uint32 index, const char* sql,
        ConnectionFlags flags) {
    // For reconnection case
    if (m_reconnecting)
        delete m_stmts[index];

    // Check if specified query should be prepared on this connection
    // i.e. don't prepare async statements on synchronous connections
    // to save memory that will not be used.
    if (!(m_connectionFlags & flags)) {
        m_stmts[index] = NULL;
        return;
    }

    MYSQL_STMT * stmt = mysql_stmt_init(m_Mysql);
    if (!stmt) {
        sLog->outSQLDriver("[ERROR]: In mysql_stmt_init() id: %u, sql: \"%s\"",
                index, sql);
        sLog->outSQLDriver("[ERROR]: %s", mysql_error(m_Mysql));
        m_prepareError = true;
    } else {
        if (mysql_stmt_prepare(stmt, sql,
                static_cast<unsigned long>(strlen(sql)))) {
            sLog->outSQLDriver(
                    "[ERROR]: In mysql_stmt_prepare() id: %u, sql: \"%s\"",
                    index, sql);
            sLog->outSQLDriver("[ERROR]: %s", mysql_stmt_error(stmt));
            mysql_stmt_close(stmt);
            m_prepareError = true;
        } else {
            MySQLPreparedStatement* mStmt = new MySQLPreparedStatement(stmt);
            m_stmts[index] = mStmt;
        }
    }
}

PreparedResultSet* MySQLConnection::Query(PreparedStatement* stmt) {
    MYSQL_RES *result = NULL;
    uint64 rowCount = 0;
    uint32 fieldCount = 0;

    if (!_Query(stmt, &result, &rowCount, &fieldCount))
        return NULL;

    if (mysql_more_results(m_Mysql)) {
        mysql_next_result(m_Mysql);
    }
    return new PreparedResultSet(stmt->m_stmt->GetSTMT(), result, rowCount,
            fieldCount);
}

bool MySQLConnection::_HandleMySQLErrno(uint32 errNo) {
    switch (errNo) {
    case 2006: // "MySQL server has gone away"
    case 2013: // "Lost connection to MySQL server during query"
    case 2048: // "Invalid connection handle"
    case 2055: // "Lost connection to MySQL server at '%s', system error: %d"
    {
        m_reconnecting = true;
        uint64 oldThreadId = mysql_thread_id(GetHandle());
        mysql_close(GetHandle());
        if (this->Open()) // Don't remove 'this' pointer unless you want to skip loading all prepared statements....
        {
            sLog->outSQLDriver("Connection to the MySQL server is active.");
            if (oldThreadId != mysql_thread_id(GetHandle()))
                sLog->outSQLDriver(
                        "Successfully reconnected to %s @%s:%s (%s).",
                        m_connectionInfo.database.c_str(),
                        m_connectionInfo.host.c_str(),
                        m_connectionInfo.port_or_socket.c_str(),
                        (m_connectionFlags & CONNECTION_ASYNC) ?
                                "asynchronous" : "synchronous");

            m_reconnecting = false;
            return true;
        }

        uint32 lErrno = mysql_errno(GetHandle()); // It's possible this attempted reconnect throws 2006 at us. To prevent crazy recursive calls, sleep here.
        ACE_OS::sleep(3); // Sleep 3 seconds
        return _HandleMySQLErrno(lErrno); // Call self (recursive)
    }

    case 1213: // "Deadlock found when trying to get lock; try restarting transaction"
        return false; // Implemented in TransactionTask::Execute and DatabaseWorkerPool<T>::DirectCommitTransaction
        // Query related errors - skip query
    case 1058: // "Column count doesn't match value count"
    case 1062: // "Duplicate entry '%s' for key '%d'"
    case 1054: // "Unknown column '%s' in 'order clause'"
        return false;

    default:
        sLog->outSQLDriver(
                "Unhandled MySQL errno %u. Unexpected behaviour possible.",
                errNo);
        return false;
    }
}
